Interesting article. I think a change will come for Kate, Juliet and possibly Charlotte, but i can't see Claire and Sun being used as anything but protective mothers.
Spoilery for 4x10 - highlight to read
If 4x10 is anything to go by i think there could be a change in leadership, as Jack will really need to rest after his surgery, so it is quite likely that Kate and/or Juliet may take charge for a bit. I don't think Jack will give up his leadership position too easily though.